textproduct: Albany

WHAT HAS CHANGED

The Storm Prediction Center has placed much of eastern New York and western New England in a Marginal Risk (level 1 of 5) for severe thunderstorms Sunday.

KEY MESSAGES

1) Showers and some thunderstorms will become widespread across most of the area Saturday night into early Sunday. Localized downpours are expected.

2) A cold front will bring isolated to widely scattered thunderstorms Sunday afternoon and evening. Some of the storms could be strong to severe.

DISCUSSION

KEY MESSAGE 1...

High pressure will build east across the region through today. Clouds will clear out from NW to SE early this morning, with sunny skies and slightly below normal temperatures this afternoon. With high pressure directly over the area tonight, lows will be cool ranging from upper 30s in the Adirondacks to near 50 in the mid Hudson Valley. Patchy/areas of fog will occur in typical sheltered valleys and near warmer bodies of water.

The high will shift east off the New England coast on Sat, with a warmer southerly flow developing. So after a cool start to the day, temperatures will warm to normal level in the afternoon. Along with warmer temperatures, moisture will also rapidly increase with PWAT anomalies increasing to +1 to +3 STDEV Sat night(greatest from ALB south). This coincides with a short wave disturbance moving into the area from the south/west and a developing surface cyclone near NYC. With the increase in moisture and forcing, widespread showers are now expected Sat night into Sun morning. While instability is lacking, deep layer moisture increase will result in localized downpours.

KEY MESSAGE 2...

After a brief break, isolated to widely scattered thunderstorms are expected to develop Sun afternoon ahead of a potent upper level short wave and associated surface cold front. Guidance indicating moderate instability developing, with 1000-1500 J/Kg SBCAPE across eastern NY, with < 1000 J/Kg in western New England. 0-6 km shear also increases to around 35-45 kt. The CAPE/shear balance may result in organized storms, with some becoming strong to severe. The threat for storms will end Sun night, as a drier and cooler air mass builds in by Mon morning.

AVIATION /10Z FRIDAY THROUGH TUESDAY/

Through 12z Saturday...High level clouds will continue to clear from NW to SE across the area this morning. VFR conditions will prevail through today. With high pressure moving overhead tonight, clear skies and light winds will lead to likely development of radiational fog, especially at KGFL/KPSF where IFR conditions are expected. Confidence is lower at KALB/KPOU. Winds today will be initially be west-northwest around 5 kt or less, increasing to 8-10 kt by later this morning. Winds will become calm tonight.

Outlook...

Saturday: No Operational Impact. NO SIG WX. Saturday Night: High Operational Impact. Definite SHRA...TSRA. Sunday: Moderate Operational Impact. Chance of SHRA...TSRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA. Monday: No Operational Impact. NO SIG WX. Monday Night: No Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Breezy. NO SIG WX.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.